[flang-commits] [flang] [Flang][OpenMP] Fix nested OpenMP mapper composition (PR #215639)

[Akash Banerjee via flang-commits]

================
@@ -138,6 +138,75 @@ class MapInfoFinalizationPass
     return findMemberByIndexPath(op, indexPath) != nullptr;
   }
 
+  static bool mapperCoversIndexPath(
+      mlir::Operation *symbolTableAnchor, mlir::FlatSymbolRefAttr mapperId,
+      llvm::ArrayRef<int64_t> indexPath,
+      llvm::SmallPtrSetImpl<mlir::Operation *> &visitedMappers) {
+    mlir::omp::DeclareMapperOp symbol =
+        mlir::SymbolTable::lookupNearestSymbolFrom<mlir::omp::DeclareMapperOp>(
+            symbolTableAnchor, mapperId);
+    if (!symbol || !visitedMappers.insert(symbol.getOperation()).second)
+      return false;
+
+    mlir::omp::DeclareMapperInfoOp mapperInfo = symbol.getDeclareMapperInfo();
+    if (!mapperInfo)
+      return false;
+
+    return llvm::any_of(mapperInfo.getMapVars(), [&](mlir::Value v) {
+      mlir::omp::MapInfoOp map =
+          mlir::dyn_cast_if_present<mlir::omp::MapInfoOp>(v.getDefiningOp());
+      return map && !map.getMembers().empty() &&
+             map.getMembersIndexAttr() &&
+             mapInfoCoversIndexPath(map, indexPath, visitedMappers);
+    });
+  }
+
+  static bool mapInfoCoversIndexPath(
+      mlir::omp::MapInfoOp map, llvm::ArrayRef<int64_t> indexPath,
+      llvm::SmallPtrSetImpl<mlir::Operation *> &visitedMappers) {
+    if (mappedIndexPathExists(map, indexPath))
+      return true;
+
+    mlir::ArrayAttr memberIndices = map.getMembersIndexAttr();
+    if (!memberIndices)
+      return false;
+
+    for (auto [memberIdx, memberIndexAttr] : llvm::enumerate(memberIndices)) {
----------------
TIFitis wrote:

Thanks for the suggestion, I've added a comment.


https://github.com/llvm/llvm-project/pull/215639